U.S. patent number 10,830,408 [Application Number 16/504,106] was granted by the patent office on 2020-11-10 for lighting devices with variable beam patterns.
This patent grant is currently assigned to HONEYWELL INTERNATIONAL INC.. The grantee listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Craig Giffen, Sunit Kumar Saxena, Newel Stephens, Anita Sure, Gowtham Kumar Vankayala.
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United States Patent |
10,830,408 |
Saxena , et al. |
November 10, 2020 |
Lighting devices with variable beam patterns
Abstract
A lighting device including a plurality of light-emitting
semiconductor devices. The light-emitting semiconductor devices are
separated into at least two subgroups. The lighting device further
includes a plurality of optics separated into at least two
subgroups, which are arranged relative to the plurality of
light-emitting semiconductor devices such that each one of the
plurality of light-emitting semiconductor devices of a first
subgroup is located at a focal point of a respective optic of a
first subgroup of the plurality of optics, and such that each one
of the plurality of light-emitting semiconductor devices of a
second subgroup is located at a focal point of a respective optic
of a second subgroup of the plurality of optics. The optical
properties of the first subgroup and second subgroup of the
plurality of optics are different. The lighting device further
includes a controller module configured to control at least two
current signals supplied from a power source to each of the at
least two subgroups of light-emitting semiconductor devices,
respectively. The controller module is configured to modify the
beam width and the peak intensity of the emitted beam of light by
varying the magnitude of the respective at least two current
signals.
Inventors: |
Saxena; Sunit Kumar (Bangalore,
IN), Sure; Anita (Bangalore, IN),
Vankayala; Gowtham Kumar (Bangalore, IN), Stephens;
Newel (Springfield, OH), Giffen; Craig (Hilliard,
OH) |
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Morris Plains |
NJ |
US |
|
|
Assignee: |
HONEYWELL INTERNATIONAL INC.
(Charlotte, NC)
|
Family
ID: |
1000004347295 |
Appl.
No.: |
16/504,106 |
Filed: |
July 5, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21S
41/148 (20180101); F21S 41/323 (20180101); H05B
45/10 (20200101); B64D 47/06 (20130101); F21S
41/285 (20180101); F21S 41/65 (20180101); B64D
47/04 (20130101); B64D 2203/00 (20130101); F21Y
2115/10 (20160801) |
Current International
Class: |
F21S
41/65 (20180101); F21S 41/32 (20180101); F21S
41/148 (20180101); F21S 41/20 (20180101); B64D
47/06 (20060101); B64D 47/04 (20060101); H05B
45/10 (20200101) |
Field of
Search: |
;315/77 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102012201494 |
|
Aug 2012 |
|
DE |
|
2018073196 |
|
Apr 2018 |
|
WO |
|
2018149935 |
|
Aug 2018 |
|
WO |
|
Primary Examiner: Le; Don P
Attorney, Agent or Firm: Lorenz & Kopf, LLP
Claims
What is claimed is:
1. A lighting device for a vehicle, the lighting device comprising:
a plurality of light-emitting semiconductor devices, the plurality
of light-emitting semiconductor devices being configured to
together emit a beam of light having a beam width and a peak
intensity, wherein the plurality of light-emitting semiconductor
devices are separated into at least two subgroups; a plurality of
optics, wherein the plurality of optics are separated into at least
two subgroups, and wherein the plurality of optics are arranged
relative to the plurality of light-emitting semiconductor devices
such that each one of the plurality of light-emitting semiconductor
devices of a first subgroup of the at least two subgroups is
located at a focal point of a respective optic of a first subgroup
of the plurality of optics, and such that each one of the plurality
of light-emitting semiconductor devices of a second subgroup of the
at least two subgroups is located at a focal point of a respective
optic of a second subgroup of the plurality of optics, and wherein
the optical properties of the first subgroup of the plurality of
optics are different to the optical properties of the second
subgroup of the plurality of optics; and a controller module
configured to control at least two current signals supplied from a
power source to each of the at least two subgroups of
light-emitting semiconductor devices, respectively, wherein the
controller module is configured to modify the beam width and the
peak intensity of the emitted beam of light by varying the
magnitude of the respective at least two current signals supplied
to each of the at least two subgroups of light-emitting
semiconductor devices.
2. The lighting device of claim 1, wherein the controller module is
configured to control the at least two current signals between
three or more discrete current values.
3. The lighting device of claim 1, wherein the plurality of optics
comprises a plurality of lenses.
4. The lighting device of claim 3, wherein the plurality of lenses
comprises a plurality of total internal reflection (TIR) lenses or
a plurality of Fresnel lenses.
5. The lighting device of claim 1, wherein the plurality of optics
comprises a plurality of reflectors.
6. The lighting device of claim 5, wherein the plurality of
reflectors comprises a plurality of parabolic reflectors.
7. The lighting device of claim 6, wherein each one of the
plurality of light-emitting semiconductor devices is positioned
such that a peak emitted light intensity direction of each
light-emitting semiconductor device is perpendicular to an axis of
a respective parabolic reflector of the plurality of parabolic
reflectors.
8. The lighting device of claim 1, wherein each subgroup of the at
least two subgroups of light-emitting semiconductor devices
comprise different combinations of LEDs from a multi-die LED.
9. A vehicle comprising a lighting device, the lighting device
comprising: a plurality of light-emitting semiconductor devices,
the plurality of light-emitting semiconductor devices being
configured to together emit a beam of light having a beam width and
a peak intensity, wherein the plurality of light-emitting
semiconductor devices are separated into at least two subgroups; a
plurality of optics, wherein the plurality of optics are separated
into at least two subgroups, and wherein the plurality of optics
are arranged relative to the plurality of light-emitting
semiconductor devices such that each one of the plurality of
light-emitting semiconductor devices of a first subgroup of the at
least two subgroups is located at a focal point of a respective
optic of a first subgroup of the plurality of optics, and such that
each one of the plurality of light-emitting semiconductor devices
of a second subgroup of the at least two subgroups is located at a
focal point of a respective optic of a second subgroup of the
plurality of optics, and wherein the optical properties of the
first subgroup of the plurality of optics are different to the
optical properties of the second subgroup of the plurality of
optics; and a controller module configured to control at least two
current signals supplied from a power source to each of the at
least two subgroups of light-emitting semiconductor devices,
respectively, wherein the controller module is configured to modify
the beam width and the peak intensity of the emitted beam of light
by varying the magnitude of the respective at least two current
signals supplied to each of the at least two subgroups of
light-emitting semiconductor devices.
10. The vehicle of claim 9, wherein the controller module is
configured to control the at least two current signals between
three or more discrete current values.
11. The vehicle of claim 9, wherein the plurality of optics
comprises a plurality of lenses.
12. The vehicle of claim 11, wherein the plurality of lenses
comprises a plurality of total internal reflection (TIR) lenses or
a plurality of Fresnel lenses.
13. The vehicle of claim 9, wherein the plurality of optics
comprises a plurality of reflectors.
14. The vehicle of claim 13, wherein the plurality of reflectors
comprises a plurality of parabolic reflectors.
15. The vehicle of claim 14, wherein each one of the plurality of
light-emitting semiconductor devices is positioned such that a peak
emitted light intensity direction of each light-emitting
semiconductor device is perpendicular to an axis of a respective
parabolic reflector of the plurality of parabolic reflectors.
16. The vehicle of claim 9, wherein each subgroup of the at least
two subgroups of light-emitting semiconductor devices comprise
different combinations of LEDs from a multi-die LED.
17. The vehicle of claim 9, further comprising a user interface
configured to receive an input from a user; and a processor
configured to control the controller module to modify the beam
width and the peak intensity of the emitted beam of light by
varying the magnitude of the respective at least two current
signals supplied to each of the at least two subgroups of
light-emitting semiconductor devices on the basis of the user
input.
18. The vehicle of claim 17, further comprising a display module to
display information about the emitted beam of light.
19. A lighting device for a vehicle, the lighting device
comprising: a plurality of light-emitting semiconductor devices,
the plurality of light-emitting semiconductor devices comprising at
least one multiple-LED die and being configured to together emit a
beam of light having a beam width and a peak intensity, wherein the
plurality of light-emitting semiconductor devices are separated
into at least two subgroups; a plurality of optics, wherein each
LED of the at least one multiple-LED die is associated with a
respective parabolic reflector, each parabolic reflector being
arranged relative to each LED of the at least one multiple-LED die
such that the peak intensity of the beam of emitted light from each
multiple-LED die is perpendicular to an axis of the respective
parabolic reflector, and wherein each multiple-LED die is located
at a focal point of each respective parabolic reflector; and a
controller module configured to control at least two current
signals supplied from a power source to each of the at least two
subgroups of light-emitting semiconductor devices, respectively,
wherein the controller module is configured to modify the beam
width and the peak intensity of the emitted beam of light by
varying the magnitude of the respective at least two current
signals supplied to each of the at least two subgroups of
light-emitting semiconductor devices.
20. The lighting device of claim 19, wherein the controller module
is configured to control the at least two current signals between
three or more discrete current values.
Description
TECHNICAL FIELD
The present disclosure generally relates to lighting devices for
vehicles, and more specifically relates to lighting devices for
aircraft.
BACKGROUND
Vehicle lighting devices, such as lighting devices for aircraft,
are known. Lighting devices are generally required on aircraft for
use as landing lights, taxi lights, search lights, and so on. These
lighting devices are used, for example, to better illuminate a
runway during take-off and landing procedures in low-light
conditions, to indicate an aircraft's position in an aerodrome to
other aircraft, or to illuminate objects.
Typically, vehicles include different types of lighting devices for
different applications. For example, an aircraft may include a taxi
light; a landing light; one or more runway lights; one or more
service illumination lights; one or more wing illumination lights;
a logo light; and one or more courtesy lights for various different
lighting applications. Some of these different types of lights may
even be included at the same location on the aircraft and differ
only in the different beam patterns or spreads produced by the
different lighting devices. For example, a taxi light typically
requires a light beam spread of about 40.degree..times.9.degree., a
runway turnoff light typically requires a beam spread of about
50.degree..times.10.degree., a cargo service illumination light
typically requires a beam spread of about
80.degree..times.20.degree., wing illumination lights typically
require a beam spread of about 13.degree..times.11.degree., and so
on.
It is desirable to reduce the need to include multiple different
types of lighting devices on a vehicle. More specifically, it would
be desirable to have a single lighting device that is able to
produce different beam patterns with different beam spreads so as
to be suitable for various different lighting applications.
BRIEF SUMMARY
This summary is provided to introduce a selection of concepts in a
simplified form that are further described below in the detailed
description section. This summary is not intended to identify key
features or essential features of the claimed subject matter, nor
is it intended to be used as an aid in determining the scope of the
claimed subject matter.
In an embodiment, there is provided a lighting device for a
vehicle, the lighting device includes a plurality of light-emitting
semiconductor devices. The plurality of light-emitting
semiconductor devices are configured to together emit a beam of
light having a beam width and a peak intensity. The plurality of
light-emitting semiconductor devices are separated into at least
two subgroups. The lighting device further includes a plurality of
optics. The plurality of optics are separated into at least two
subgroups, and are arranged relative to the plurality of
light-emitting semiconductor devices such that each one of the
plurality of light-emitting semiconductor devices of a first
subgroup of the at least two subgroups is located at a focal point
of a respective optic of a first subgroup of the plurality of
optics, and such that each one of the plurality of light-emitting
semiconductor devices of a second subgroup of the at least two
subgroups is located at a focal point of a respective optic of a
second subgroup of the plurality of optics. The optical properties
of the first subgroup of the plurality of optics are different to
the optical properties of the second subgroup of the plurality of
optics. The lighting device further includes a controller module
configured to control at least two current signals supplied from a
power source to each of the at least two subgroups of
light-emitting semiconductor devices, respectively, wherein the
controller module is configured to modify the beam width and the
peak intensity of the emitted beam of light by varying the
magnitude of the respective at least two current signals supplied
to each of the at least two subgroups of light-emitting
semiconductor devices.
In an embodiment, there is provided a vehicle comprising a lighting
device, the lighting device comprising a plurality of
light-emitting semiconductor devices. The plurality of
light-emitting semiconductor devices are configured to together
emit a beam of light having a beam width and a peak intensity. The
plurality of light-emitting semiconductor devices are separated
into at least two subgroups. The lighting device further includes a
plurality of optics. The plurality of optics are separated into at
least two subgroups, and are arranged relative to the plurality of
light-emitting semiconductor devices such that each one of the
plurality of light-emitting semiconductor devices of a first
subgroup of the at least two subgroups is located at a focal point
of a respective optic of a first subgroup of the plurality of
optics, and such that each one of the plurality of light-emitting
semiconductor devices of a second subgroup of the at least two
subgroups is located at a focal point of a respective optic of a
second subgroup of the plurality of optics. The optical properties
of the first subgroup of the plurality of optics are different to
the optical properties of the second subgroup of the plurality of
optics. The lighting device further includes a controller module
configured to control at least two current signals supplied from a
power source to each of the at least two subgroups of
light-emitting semiconductor devices, respectively, wherein the
controller module is configured to modify the beam width and the
peak intensity of the emitted beam of light by varying the
magnitude of the respective at least two current signals supplied
to each of the at least two subgroups of light-emitting
semiconductor devices.
In an embodiment, there is provided a lighting device for a
vehicle. The lighting device includes a plurality of light-emitting
semiconductor devices, the plurality of light-emitting
semiconductor devices comprising at least one multiple-LED die and
being configured to together emit a beam of light having a beam
width and a peak intensity, wherein the plurality of light-emitting
semiconductor devices are separated into at least two subgroups.
The lighting device also include a plurality of optics, wherein
each LED of the at least one multiple-LED die is associated with a
respective parabolic reflector, each parabolic reflector being
arranged relative to each LED of the at least one multiple-LED die
such that the peak intensity of the beam of emitted light from each
LED is perpendicular to an axis of the respective parabolic
reflector, and wherein each LED is located at a focal point of each
respective parabolic reflector. The lighting device also includes a
controller module configured to control at least two current
signals supplied from a power source to each of the at least two
subgroups of light-emitting semiconductor devices, respectively,
wherein the controller module is configured to modify the beam
width and the peak intensity of the emitted beam of light by
varying the magnitude of the respective at least two current
signals supplied to each of the at least two subgroups of
light-emitting semiconductor devices.
Other desirable features will become apparent from the following
detailed description and the appended claims, taken in conjunction
with the accompanying drawings and this background.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the subject matter may be derived
from the following detailed description taken in conjunction with
the accompanying drawings, wherein like reference numerals denote
like elements, and wherein:
FIG. 1 shows a schematic of a lighting device in accordance with
exemplary embodiments;
FIG. 2 shows another schematic of a lighting device in accordance
with exemplary embodiments;
FIG. 3 shows a graph illustrating a change in beam spread and peak
intensity;
FIG. 4 shows a lighting device in accordance with exemplary
embodiments;
FIG. 5 shows another lighting device in accordance with exemplary
embodiments;
FIG. 6 shows another lighting device in accordance with exemplary
embodiments;
FIG. 7 shows another view of the lighting device shown in FIG.
6;
FIG. 8 shows a view of a multi-die LED incorporated into a lighting
device in accordance with exemplary embodiments;
FIGS. 9A and 9B show graphs illustrating a change in beam spread
and peak intensity;
FIG. 10 shows images illustrating a variation in beam spread;
FIGS. 11A and 11B show graphs illustrating a change in beam spread
and peak intensity;
FIG. 12 shows images illustrating a variation in beam spread;
FIG. 13 shows a view of different types of reflectors used in a
lighting device according to exemplary embodiments;
FIG. 14 shows a lighting device with the reflectors shown in FIG.
13; and
FIG. 15 shows a schematic of a vehicle including a lighting device
in accordance with exemplary embodiments.
DETAILED DESCRIPTION
The following detailed description is merely illustrative in nature
and is not intended to limit the embodiments of the subject matter
or the application and uses of such embodiments. As used herein,
the word "exemplary" means "serving as an example, instance, or
illustration." Thus, any embodiment described herein as "exemplary"
is not necessarily to be construed as preferred or advantageous
over other embodiments. All of the embodiments described herein are
exemplary embodiments provided to enable persons skilled in the art
to make or use the systems and methods defined by the claims.
Furthermore, there is no intention to be bound by any expressed or
implied theory presented in the preceding Technical Field,
Background, Brief Summary or the following Detailed
Description.
For the sake of brevity, conventional techniques and components may
not be described in detail herein. Furthermore, any connecting
lines shown in the various figures contained herein are intended to
represent example functional relationships and/or physical
couplings between the various elements. It should be noted that
many alternative or additional functional relationships or physical
connections may be present in an embodiment of the present
disclosure.
With reference to FIG. 1, a schematic of a lighting device 100 for
a vehicle, for example an aircraft, is shown. The lighting device
100 may include a power source 102 for supplying electrical energy
to other components of the lighting device 100. Alternatively, the
power source may be external to the lighting device 100. A
controller module 104 is operably connected to the power source
102. A first subgroup of light-emitting semiconductor devices 106a
and a second subgroup of light-emitting semiconductor devices 106b
are operably connected to the controller module 104. In various
exemplary embodiments, further subgroups of light-emitting
semiconductor devices are operably connected to the controller
module 104. The controller module 104 is configured to
independently control the amount of electrical energy supplied to
each subgroup 106a, 106b of light-emitting semiconductor devices in
a manner that will be described in more detail below.
A first subgroup of optics 108a is arranged proximate to the first
subgroup of light-emitting semiconductor devices 106a. Similarly, a
second subgroup of optics 108b is arranged proximate to the second
subgroup of light-emitting semiconductor devices 106b. Each of the
first and second subgroups of optics 108a, 108b are arranged with
respect to the first and second subgroups of light-emitting
semiconductor devices 106a, 106b such that each one of the
light-emitting semiconductor devices is positioned at a focal point
of a respective optic. In other words, each one of the
light-emitting semiconductors devices of the first subgroup of
light-emitting semiconductor devices 106a is positioned at a focal
point of an optic of the first subgroup of optics 108a, and each
one of the light-emitting semiconductors devices of the second
subgroup of light-emitting semiconductor devices 106b is positioned
at a focal point of an optic of the second subgroup of optics 108b.
The optical properties of optics of the first subgroup of optics
108a are different from the optical properties of the optics of the
second subgroup of optics 108b, for reasons that will be explained
in more detail below.
By fixedly positioning each light-emitting semiconductor device at
a focal point of a respective optic, several advantages are
achieved. Firstly, if a light-emitting semiconductor device is not
positioned at the focal point of each optic, the light emitted by
the light-emitting semiconductor device may be altered by the optic
in a non-uniform manner. This non-uniform altering of the emitted
light may cause a reduction in the overall amount of illumination
achieved by the light-emitting semiconductor device. Conversely, by
positioning the light-emitting semiconductor device at the focal
point of the optic, the emitted light may be altered in a more
uniform manner, thereby reducing this potential loss in
illumination. Secondly, positioning the light-emitting
semiconductor device at the focal point of the optic allows for the
collection efficiency of the optic to be maximized, because a
minimal amount of emitted light is lost by refraction or reflection
off surfaces of the optic. Thirdly, by including an individual
optic for each individual light-emitting semiconductor device
instead of including an optic that covers multiple light-emitting
semiconductor devices, the above advantages can be achieved for
each one of the light-emitting semiconductor devices. Fourthly, by
including a separate optic for each individual light-emitting
semiconductor device, the overall size of the lighting device can
be reduced, as each optic can be kept small in size as compared to
an device that includes a larger optic that covers multiple
light-emitting semiconductor devices.
However, by positioning each light-emitting semiconductor device at
a focal point of each optic, one manner of altering the shape and
spread of the beam of light emitted by the semiconductor device,
namely by varying the position of the light-emitting device with
respect to the optic, is no longer possible. In particular, varying
the position of the light-emitting device with respect to the optic
may move the light-emitting device away from the focal point of the
optic. As explained above, one object of the present disclosure is
to provide a lighting device that is able to produce multiple
different types of beam having different beam spreads. As such,
another technique of producing different types of overall beam with
different beam spreads is required that is suitable for
light-emitting semiconductor devices being fixedly positioned with
respect to the optics.
The lighting device 100 is configured to produce different types of
beam patterns with different beam spreads by varying the amount of
electrical energy, for example the current, supplied to each
subgroup 106a, 106b of light-emitting semiconductor devices. In
this manner, the different light beams produced by the first and
second subgroups of light-emitting devices and optics can be varied
as desired so as to vary the beam pattern of the overall composite
beam emitted by the lighting device 100, which composite beam is
the result of the combination of the individual light beams
produced by the first and second subgroups of light-emitting
devices.
The manner in which the overall composite beam emitted by the
lighting device 100 may be varied is explained with respect to FIG.
2. As shown in FIG. 2, the lighting device 100 includes an area
(exemplified in this figure as an inner radial ring) including the
first subgroup of light-emitting semiconductor devices 106a and an
area (exemplified in this figure as an outer radial ring) including
the second subgroup of light-emitting semiconductor devices 106b.
Although the positions of the first and second subgroups of
light-emitting semiconductor devices shown in this figure are
exemplified by inner and outer radial rings, it will be appreciated
that many different configurations and positions for the different
subgroups of light-emitting semiconductor devices are possible.
The controller module 104 is configured to vary the current
supplied to each light-emitting semiconductor device subgroup. In
the example of FIG. 2, the controller module 104 is configured to
supply an equal amount of current from the power source 102 to each
subgroup of light-emitting semiconductor devices from time t0 to
time t1. The resultant composite overall beam pattern generated by
the light emitted from both subgroups therefore has a first
configuration from time t0 to time t1, with a first beam spread and
a first peak intensity. From time t1 to time t2, the controller
module 104 decreases the current supplied to the first subgroup of
light-emitting semiconductor devices and maintains the amount of
current supplied to the second subgroup of light-emitting
semiconductor devices. Due to the different optical properties of
the first subgroup of optics 108a associated with the first
subgroup of light-emitting semiconductor devices 106a as compared
to the second subgroup of optics 108b associated with the second
subgroup of light-emitting semiconductor devices 106b, the shape of
the overall composite beam emitted by the lighting device will also
vary over this time period t1 to t2. For example, if the first
subgroup of optics 108a and associated light-emitting semiconductor
devices 106a are configured to produce a narrower beam spread as
compared to the second subgroup of optics 108b and the associated
second subgroup of light-emitting semiconductor devices 106b, as
the amount of current supplied to the first subgroup of
light-emitting semiconductor devices 106a decreases the composite
overall beam spread will increase. At time t2, the controller
module supplies no current to the first subgroup of light-emitting
semiconductor devices 106a. As such, at time t2 to t3, the
composite beam emitted by the lighting device 100 corresponds
solely to the individual beam produced by the second subgroup of
light-emitting semiconductor devices 106b and optics 108b, with no
contribution to this overall composite beam from the first subgroup
of light-emitting semiconductor devices 106a.
At time t3, the controller module 104 begins decreasing the amount
of current supplied to the second subgroup of light-emitting
semiconductor devices 106b and simultaneously increasing the amount
of current supplied to the first subgroup of light-emitting
semiconductor devices 106a. As such, from time t3 to time t4, the
shape of the composite overall beam emitted by the lighting device
100 varies. In particular, if the first subgroup of optics 108a and
associated light-emitting semiconductor devices 106a are configured
to produce a narrower beam spread as compared to the second
subgroup of optics 108b and associated second subgroup of
light-emitting semiconductor devices 106a, as the amount of current
supplied to the first subgroup of light-emitting semiconductor
devices 106a increases and the amount of current supplied to the
second subgroup of light-emitting semiconductor devices 106b
decreases, the composite overall beam spread will decrease. In
other words, the contribution to the overall composite beam will
trend towards the individual beam produced by the first subgroup of
light-emitting semiconductor devices 106a and associated optics
108a as the current to the first subgroup of light-emitting
semiconductor devices increases and the current supplied to the
second subgroup of light-emitting semiconductor devices
decreases.
At time t4, the controller module 104 supplies no current to the
second subgroup of light-emitting semiconductor devices 106b and
supplies a non-zero amount of current to the first subgroup of
light-emitting semiconductor devices 106a. As such, at time t4 to
time t5, the properties of the composite beam emitted by the
lighting device are defined solely by the properties of the first
subgroup of light-emitting semiconductor devices 106a and first
subgroup of optics 108a.
As can be seen from FIG. 2, by varying the current supplied to each
subgroup of light-emitting semiconductor devices over a range of
discrete values (for example over three or more discrete values) in
a quasi-continuous manner, a greater range of potential composite
beam patterns can be achieved as compared to a hypothetical system
where each subgroup of light-emitting semiconductor devices is
simply switched "on" or "off", i.e., between a zero and non-zero
current value.
Additional information as to how the composite beam emitted by the
lighting device 100 can be varied as a result of the variation in
current supplied to each subgroup of light-emitting semiconductor
devices can be seen in FIG. 3 when read in conjunction with Table 1
below.
TABLE-US-00001 TABLE 1 Current supplied to second Current supplied
subgroup of light to first subgroup Composite Composite emitting of
light emitting Beam Beam Peak semiconductor semiconductor Width @
Intensity devices devices 10% (cd) Option 1 1.5 A 0 A 14.5.degree.
187,992 Option 2 1.25 A 0.25 15.degree. 171,392 Option 3 1 A 0.5 A
17.degree. 154,113 Option 4 1.5 A 1.5 A 20.degree. 211,982 Option 5
0.75 A 0.75 A 21.degree. 128,937 Option 6 0.5 A 1 A 23.degree.
102,123 Option 7 0.25 A 1.25 A 31.degree. 65,721 Option 8 0 A 1.5 A
38.degree. 23,990
As can be seen in FIG. 3, various illustrative options are shown,
these options corresponding to composite beams having different
beam spreads and peak intensities, all of which may be output by
the lighting device 100 by varying the amount of current supplied
to the first and second subgroups of light-emitting semiconductor
devices 106a, 106b. The various currents supplied to the first and
second subgroups of light-emitting semiconductor devices 106a, 106b
to produce these different types of composite beam pattern are
shown in Table 1. As can be appreciated, the adaptability of the
lighting device to produce different types of composite beam
pattern is increased with the lighting device according to
exemplary embodiments. As can be further appreciated, further beam
configurations are possible depending on the resolution and range
of the controller module 104.
In exemplary embodiments, each subgroup of light-emitting
semiconductor devices 106a, 106b corresponds to a group of LEDs,
for example a multi-die LED. In alternative exemplary embodiments,
each subgroup of light-emitting semiconductor devices corresponds
to a single LED.
In exemplary embodiments, the optics forming part of the first and
second subgroups of optics may be lenses, for example a total
internal reflection (TIR) lens. An exemplary lighting device 400
including lenses is shown in FIG. 4. As can be seen in FIG. 4, the
lighting device 400 includes first and second subgroups of lenses
406a, 406b disposed over the first and second subgroups of
light-emitting semiconductor devices, respectively. The first
subgroup of lenses 406a have different optical properties to the
second subgroup of lenses 406b.
In an embodiment, the lenses of the first and/or second subgroups
are transparent and uncoated. In another embodiment, the lenses are
transparent and coated with a lens coating, such as an
anti-reflective, anti-fog and/or scratch resistant coating, or
another type of coating. In yet another embodiment, the lenses are
translucent and/or partially or wholly opaque to certain
wavelengths of light. The lens coating and/or lenses 406a, 406b may
be adapted to the intended function of the lighting device 400.
In alternative exemplary embodiments, the optics forming part of
the first and second subgroups of optics may be reflectors. An
exemplary lighting device 500 having reflectors 508a, 508b as the
optics associated with the first and second subgroups of
light-emitting semiconductor devices. The lighting device 500
comprises a housing 501 surrounding the light-emitting
semiconductor devices and the reflectors 508a, 508b. The housing
503 includes a central axis 503. In the lighting device 500, it is
noted that the first and second subgroups of light-emitting
semiconductor devices are mounted laterally, such that the peak
light emission direction of each light-emitting semiconductor
device is perpendicular to the central axis 503 of the lighting
device 500.
Another a lighting device 600 having reflectors is shown in FIG. 6.
As can be seen in FIG. 6, the shape and positions of the different
subgroups of reflectors 608a, 608b may vary depending on the
desired functionality of the lighting device 500. A top view of the
lighting device 600 is shown in FIG. 7.
The lighting devices 500, 600 may include two or more multiple die
LEDs as the first and second subgroups of light-emitting
semiconductor devices. One example of a multiple die LED is a 5-die
LED 550, shown in FIG. 8. As can be seen in FIG. 8, a 5-die LED 550
includes 5 LEDs arranged proximate to one another, wherein the
current supplied to each LED of the 5-die LED 550 can be varied
independently by the controller module so as to independently vary
the luminosity of each LED. Each LED is associated with an optic
508, for example a respective small lens or reflector, or a
reflector that is shaped so as to form a series of respective
optics for each LED. In an exemplary embodiment not shown in FIG.
8, the optic 508 is shaped so as to correspond to a series of
parabolic reflectors, with each LED of the multiple-die LED being
located at a focal point of a respective one of the parabolic
reflectors such that the peak emitted light intensity direction of
each LED is perpendicular to an axis of each respective parabolic
reflector. Such an arrangement allows for improved optical
efficiency.
The effects of varying the current supplied to various LEDs of the
5-die LED are shown in FIGS. 9A and 9B in conjunction with Table 2
shown below.
TABLE-US-00002 TABLE 2 Beam Width @ 10% Peak Current Horizontal
Vertical Intensity (cd) All 5 LEDs 1 A 31.3.degree. 13.3.degree.
37,679 Central 3 LEDs 1 A 25.3.degree. 10.8.degree. 37,609 Central
LED 1 A 10.2.degree. 8.5.degree. 34,767
As can be seen in FIGS. 9A and 9B, by illuminating all 5 LEDs of
the 5-die LED, the central 3 LEDs of the 5-die LED or the central
LED of the 5-die LED, different overall beam patterns result, with
different beam widths and different peak intensities. The
horizontal and vertical scans of the overall beam patterns are
shown in FIG. 7, and show an increasing beam spread as current is
supplied to more of the LEDs of the 5-die LED. Although FIGS. 9A
and 9B show the variation of the current being supplied to each LED
of the 5-die LED being of an ON/OFF form, it will be appreciated
that an even greater range of beam spreads can be achieved by
varying the current supplied to the LEDS of the 5-die LED over
three or more discrete values (for example, supplying 1.5 A to the
central LED, 1 A to the LEDs either side of the central LED, and
0.5 A to the outermost LEDs).
FIG. 10 shows intensity plots for the three situations given in
Table 2. The left-most plot 1 of FIG. 10 shows the light intensity
distribution of the overall beam from the lighting device when only
the central LED is supplied with current, the central plot 2 of
FIG. 10 shows the light intensity distribution when the central
three LEDs are supplied with current, and the right-most plot 3 of
FIG. 10 shows the light intensity distribution when all five LEDs
are supplied with current. As can be seen in FIG. 10, as more LEDs
of the 5-die LED are illuminated, the spread of the emitted
composite beam increases.
Further effects of varying the current supplied to various LEDs of
the 5-die LED are shown in FIGS. 11A and 11B in conjunction with
Table 3 shown below.
TABLE-US-00003 TABLE 3 Beam Width Peak (Degrees) @ 10% Intensity
Current Horizontal Vertical (cd) 2nd and 4th Die 1 A 36.8.degree.
12.8.degree. 11,087 Central die 0.25 A 1st 2nd, 4th & 5th 1 A
53.5.degree. 17.1.degree. 11,166 Die Central die 0.25 A
As can be seen in FIGS. 11A and 11B and Table 3, changing the
amount of current supplied to various LEDs of the 5-die LED alters
the width and peak intensity of the overall emitted beam from the
lighting device.
FIG. 12 shows intensity plots for the two situations given in Table
3. The left-most plot 4 of FIG. 12 shows the light intensity
distribution of the overall beam from the lighting device when the
central LED is supplied with 0.25 A of current and the 2.sup.nd and
4.sup.th LEDs are supplied with 1 A of current, and the right-most
plot 5 of FIG. 12 shows the light intensity distribution of the
overall beam from the lighting device when the central LED is
supplied with 0.25 A of current and the remainder of the LEDs are
supplied with 1 A of current. As can be seen in FIG. 12, as more
LEDs of the 5-die LED are illuminated, the spread of the emitted
composite beam increases and the peak intensity also increases.
As will be appreciated from the above explanation, varying the beam
spread and peak intensity of the composite beam emitted from the
lighting device without needed to move the light-emitting
semiconductors relative to the optics negates the need for a
movement mechanism, thereby reducing the possibility of mechanical
failure and decreasing the cost of the overall lighting device.
As explained above, the optical properties of the first and second
subgroups of optics are different. A representation of different
types of reflector having different optical properties that may be
used as the different optics of the first and second subgroups of
optics in a lighting device 700 is shown in FIG. 13. The reflectors
708a, 708b may be arranged in a manner of different ways so as to
have different optical properties. One exemplary embodiment in
which two different types of reflectors 708a, 708b are arranged
proximate to one another is shown in FIG. 10. As can be seen in
FIG. 13, the size and shape of the different types of reflectors
708a, 708b confer different optical properties. These different
optical properties realize different optical effects, for example a
different amount of beam spread of a beam of light reflected off
the surface of each reflector.
In an exemplary embodiment, the reflectors 708a, 708b are parabolic
reflectors, wherein the direction of peak intensity of emitted
light from each light-emitting semiconductor device associated with
each reflector is perpendicular to the axis of the parabola.
FIG. 14 shows a top view of the lighting device 700 having two
different types of reflectors 708a and 708b as the first and second
subgroups of optics.
As explained above, at least two subgroups of optics are included
in the lighting device of exemplary embodiments, with each subgroup
of optics being associated with a respective subgroup of
light-emitting semiconductor devices. In various exemplary
embodiments, more than two subgroups of optics are included in the
lighting device. In various exemplary embodiments each subgroup of
optics comprises a different type of reflector. However, in other
exemplary embodiments each subgroup of optics may comprise a lens
with different optical properties. In yet other exemplary
embodiments, the different subgroups of optics may correspond to a
combination of lenses and reflectors, or still further optical
devices.
The inclusion of three or four (or more) different subgroups of
optics allows for an even greater variety of different beam spreads
and patterns to be emitted by the lighting device as compared to a
lighting device having two different subgroups of optics.
In order to still further increase the amount of different beam
patterns and spreads which can be emitted by the lighting device,
in various exemplary embodiments the different subgroups of
light-emitting semiconductor devices also have different optical
properties.
For example, one subgroup of light-emitting semiconductor devices
may include square LEDs, such as CREE XHP35 LEDs. Another subgroup
of light-emitting semiconductor devices may include rectangular
LEDs, such as OSRAM Ostar LEDs. By varying the amount of electrical
energy supplied to these different types of LEDs forming the
different subgroups of light-emitting semiconductor devices, yet
further different beam patterns and spreads may be achieved. The
type and position of the light-emitting semiconductor devices may
be selected based on the desired functionality of the lighting
device.
In order to still further increase the variety of functions
achievable by the lighting device, in exemplary embodiments certain
subgroups of light-emitting semiconductor devices include infra-red
(IR) LEDs. Incorporation of IR LEDs into certain subgroups of
light-emitting semiconductor devices allows for dual-IR and visible
light operation of the lighting device.
In exemplary embodiments, the lighting device is incorporated into
a vehicle, for example an aircraft. For example, the lighting
device may be incorporated into a dedicated fitting, such as a PAR
fitting, of the vehicle. In an exemplary embodiment, the lighting
device includes a connector configured to electrically connect
components of the lighting device 100 to an external power supply
(not shown) when the lighting device is fitted into the vehicle
fitting. In another embodiment, the connector also provides for a
physical connection between the lighting device and the vehicle
fitting to fixedly secure the lighting device to the vehicle
fitting as well as providing an electrical connection. In yet
another embodiment, the connector may only provide a physical
connection, and electrical energy is supplied to the lighting
device components via a power source forming part of the lighting
device.
In exemplary embodiments, when the lighting device 100 is
incorporated into a vehicle, the lighting device 100 is
controllable by an occupant of the vehicle. FIG. 15 shows a
schematic of a vehicle 1000 including a lighting device 100 in
accordance with exemplary embodiments. The vehicle further includes
a user interface module 1100, which comprises, for example a
switch, dial, touchscreen or other input device. The vehicle
further optionally includes a display module 1300. The user
interface module 1100 and optional display module 1300 are operably
connected to a processor 1200. The lighting device 100 is also
operably connected to the processor 1200. In use, an occupant of
the vehicle 1000 may interact with the user interface module 1100
so as to select a particular mode for the lighting device 100. For
example, the occupant may interact with the user interface module
so as to configure the lighting device 100 as a wide beam search
light. In response to this input from the user interface module
1100, the processor 1200 is configured to transmit an instruction
to the controller module of the lighting device so as to vary the
currents supplied to the two or more subgroups of light-emitting
semiconductor devices so as to modify the beam spread of the
composite beam emitted by the lighting device to be around
40.degree..times.9.degree.. The display module 1300 may display the
current setting of the lighting device.
In another example, the occupant may interact with the user
interface module so as to configure the lighting device 100 as a
narrow beam search light. In response to this input from the user
interface module 1100, the processor 1200 is configured to transmit
an instruction to the controller module of the lighting device so
as to vary the currents supplied to the two or more subgroups of
light-emitting semiconductor devices so as to modify the beam
spread of the composite beam emitted by the lighting device to be
around 10.degree..times.10.degree.. In this manner, the single
lighting device 100 may be configured for different lighting
functions.
As will be appreciated from the above explanation, multiple
advantages are realized by the lighting device according to
exemplary embodiments. One further advantage associated with the
lighting device of exemplary embodiments, in addition to those
presented above, is that a single lighting device may be
manufactured and pre-configured for various different lighting
applications. As such, the manufacturing process for manufacturing
different lighting devices for different lighting applications may
be simplified, since the required beam spreads and peak intensities
for the different lighting applications can be obtained via
supplying different currents to different subgroups of
light-emitting semiconductor devices in the lighting device instead
of changing the design of the lighting device for each particular
application.
While at least one exemplary embodiment has been presented in the
foregoing detailed description, it should be appreciated that a
vast number of variations exist. It should also be appreciated that
the exemplary embodiment or exemplary embodiments are only
examples, and are not intended to limit the scope, applicability,
or configuration of the disclosure in any way. Rather, the
foregoing detailed description will provide those skilled in the
art with a convenient road map for implementing the exemplary
embodiment or exemplary embodiments. It should be understood that
various changes can be made in the function and arrangement of
elements without departing from the scope of the disclosure as set
forth in the appended claims and the legal equivalents thereof.
* * * * *